This invention relates generally to a device for installing metal corner strip used in conjunction with a wallboard assembly. More particularly, this invention relates to a device for installing metal cornerstrip or cornerbead on wallboard wherein the installation device is fluid activated, preferably by air.
Wallboard or sheetrock is well known and is used to provide smooth wall surfaces to the interiors of buildings. As is also well known, the corner or edge where two wallboards form a 90.degree. angle require a metal cornerstrip to protect the wallboard corners from breakage. This metal cornerstrip comprises a flat metal sheet which is bent at an angle along the longitudinal center thereof. Typically, the flat metal sheet has spaced openings therethrough for receiving fasteners or the like. Metal cornerstrip of this type is well known by the term "cornerbead" and shall be referred to by that term hereinafter.
As mentioned, cornerbead is typically attached to the corner of a pair of wallboard sections using threaded fasteners or the like. It will be appreciated that the use of threaded fasteners to attach the cornerbead can be time consuming and therefore undesirable. Attempts to mechanically attach cornerbead by fastener means are known. For example, hammer actuated cornerbead crimping or clincher devices are known wherein a hammer actuates a cornerbead crimping device which then drives the cornerbead into the wallboard through a crimping action. Typically, these devices comprise a pair of articulated arms pivotably attached to a support which is received in a housing. The arms terminate at a pair of pointed teeth. When the housing is placed flush up against a cornerbead, a blow of the hammer against the support will drive the articulated arms against the cornerbead and pivot the teeth into the cornerbead thereby providing the required crimping action.
While suited for its intended purposes, the hammer actuated cornerbead crimper requires the installer to use both hands, one for holding the crimper and the other for driving the hammer. This process is both difficult and cumbersome and therefore a power actuated crimper is desired. Known manual operated crimpers are described in U.S. Pat. Nos. 2,859,445, 2,944,262 and 3,170,162. Known power actuated crimpers are disclosed in U.S. Pat. Nos. 4,893,493, 4,989,438 and 5,040,400. However, there are no crimping devices presently known which allow both manual or powered operation. This leads to several disadvantages and perceived deficiencies.